With the upgrading of product quality in the machinery industry and the expansion of the export casting market due to the increase in international demand for castings, more and more domestic companies (or enterprises) choose to switch from green sand wet casting process to self-hardening resin sand casting process. Compared with green sand wet casting process, self-hardening resin sand casting process has the following advantages: good casting surface quality, high dimensional accuracy, low scrap rate, wide range of applications, low requirements for workers'' technical level, greatly reducing the labor intensity of workers and improving the working environment. However, its shortcoming is the higher casting cost, in order to reduce the casting cost, sanzhuji combined with the self-hardening resin sand regeneration process, it is recommended to consider from several aspects, such as equipment, raw materials, production process.

1、choose the appropriate self-hardening resin sand production equipment is the premise of reducing the cost of resin sand casting in the choice of resin sand production equipment, not only to consider the actual situation of the enterprise, choose the appropriate price of the equipment, but also should consider the operating costs of the equipment, the main should consider the following.
1.1 to pay attention to the choice of dust removal equipment in the choice of production equipment, most enterprises tend to pay more attention to the quality of sand mixing equipment and regeneration equipment, while ignoring the quality of dust removal equipment. In fact, the dust removal equipment is good or bad, directly affects the quality and cost of recycled sand, if the dust removal equipment is not good, not only affects the working environment, pollution of the air, more importantly, affects the micro powder content of recycled sand, the direct result is to lead to increased production costs due to the increase in the amount of resin added when mixing sand.
1.2 to consider the reliability of the equipment and its maintenance fee equipment manufacturer''s processing means, assembly level and equipment configuration level determines the reliability of its production equipment, if the reliability of the equipment is poor, the probability of equipment failure is large, the number of times to replace equipment parts increases, the utilization rate of the equipment is reduced, so that not only increases the workload of maintenance workers, increase the maintenance fee of equipment, but also lowered the production efficiency and increased production costs.
1.3 To consider the energy consumption of equipment under the premise of meeting the process requirements, try to reduce the installed capacity, avoid the phenomenon of large horse-drawn carriage, make full use of inherent resources, reduce unnecessary energy waste, achieve full load of equipment utilization and maximize energy utilization, increase enterprise efficiency and social benefits.

2、the development of a correct and reasonable production process is the key to reducing the cost of resin sand casting production process is developed reasonably or not, directly affects the yield of the casting, casting quality and casting costs, in the development of the production process, the main should determine the following.
2.1 to determine the appropriate LOI value of recycled sand LOI value is an important indicator to measure the rate of regeneration of sand decontamination, is also closely related to the amount of sand gassing and casting porosity defects, cast iron parts are generally produced using furan resin sand, practice has proved that LOI value control at about 3% can fully meet production requirements, while some enterprises require LOI value control at 2.5% or less In order to achieve this purpose, it is necessary to increase the equipment, or increase the number of sand regeneration, or add more new sand, which will undoubtedly increase the investment in equipment and regeneration costs and raw material costs. Our company in the production process, gradually relax the LOI value control index from about 3% to about 4%, due to the process and proper management, and not because of the LOI value change and affect the quality of the casting index.
2.2 Determine the appropriate casting process parameters
2.21 Determine the suitable final strength Generally, after the resin sand is mixed and hardened by itself for about 24 hours, it can reach the highest strength, that is, the final strength. Due to the different production conditions and production scale of each enterprise, the time interval between molding and pouring is not necessarily more than 24 hours, so the final strength should be determined depending on the enterprise. Smaller scale, the implementation of a few days a furnace system of enterprises, can be used 24 hours final strength standards; casting curing time does not exceed the 24 hours of enterprises, the strength reached before pouring as the final strength standards. At the same time, in production to overcome the tendency of two aspects: on the one hand, to ensure the quality and blindly improve the strength, so that the casting cost increases, resulting in waste; on the other hand is to protect the cost and depress the strength, resulting in unstable quality, fluctuations in the range, so that the quality of castings by raw materials and the operator''s influence is greater. Each enterprise should determine the appropriate final strength according to their own situation, so as to achieve the maximum savings in resin and curing agent to ensure the quality of the casting, reduce the cost of casting.
2.22 Determine the appropriate sand-iron ratio Self-hardening resin sand has a smaller sand eating capacity than that of clay sand because of its high strength, mold starting after curing and flat parting surface, but its sand-iron ratio also has certain requirements. If the casting sand-iron ratio is too high, the production process will waste resin and curing agent and produce a large block of waste sand, which will increase the burden on the regenerator, reduce the release rate, increase the LOI value, and increase the possibility of pores in the casting; if the sand-iron ratio is too low, it is easy to produce a runner when pouring, and the casting is easy to produce deformation. According to our experience, the sand-iron ratio should be selected as 2.2~3:1.
2.23 determine the appropriate molding process casting yield rate, directly affects the casting cost, the appropriate molding process not only to ensure the quality of castings, but also to reduce casting costs, reduce the casting scrap rate is one of the most obvious and direct measures to reduce casting costs. In determining the molding process, try to make special sand box, box wall more air holes, the model to do the actual sample, using the template modeling, pouring system using ceramic tubes, internal sprue to take more and disperse, paint coating evenly, do not leak coating, set up more air bubble, to ensure that the core exhaust smoothly.

3、the correct choice of raw materials is the basis for reducing the cost of resin sand casting. The choice of raw materials has a greater impact on the cost of casting, which has been recognized by the vast majority of peers, because the raw materials are good or bad, on the one hand, affects the amount of various materials added and consumed, on the other hand, affects the quality of the casting index.
3.1 the choice of raw sand is divided into ordinary sand, washed sand, scrubbing sand and other types of sand, due to scrubbing sand contains little mud, so it can greatly reduce the waste of resin, should be preferred, followed by washed sand, but never use the raw sand without treatment. Scrub sand itself is not expensive, generally 50 yuan / t to 70 yuan / t, but its freight costs are high, choose the type of sand, one should follow the principle of selection of the nearest, so that on the one hand can reduce the expensive freight, on the other hand, to protect the supply, does not affect production. Second, we should try to use the raw sand with low angular coefficient. At the same time, due to the scrub sand production enterprises of the technical level and equipment equipment level is different, the quality of its production of scrub sand is also different, therefore, if there are conditions, in determining the use of sand, scrub sand production enterprises should be inspected to examine its technical condition, equipment condition and sand source condition, etc., and find each other from the sand quality control results. In short, in the process of choosing the original sand, it is best to make the production cost to the lowest degree by means of experimental comparison, with reference to other aspects of the problem, under the premise of ensuring production and quality.
3.2 The choice of resin is more expensive, generally in 10000 yuan / t or so, so its impact on the casting cost is greater, while the quality of the resin produced by the manufacturer''s production equipment varies, there are large differences. If you choose a poor quality resin, not only affect the quality of the sand, resulting in increased casting scrap, but also increase the amount of resin added, the direct result is to increase the cost of casting, so the choice of raw materials, not only according to the technical data provided by the manufacturer to determine, but should be the manufacturer''s production equipment, production process and quality control means to understand, and try to carry out their own indicators of the resin Test or ask the relevant inspection department with good reputation to test, or learn from the experience of similar manufacturers, or choose the products of well-known large enterprises with good reputation.
3.3 other raw materials selection of other raw materials, including curing agent, paint, binder, release agent, sealing clay bar, etc., the impact of these raw materials on the quality of the casting is not the main, but the impact on the cost of casting can not be ignored, such as the amount of curing agent added to the different, not only due to the impact on the productivity of the molding process and affect the production cost, but also affect the cost of materials. Therefore, the choice of other raw materials principle is to consider both its quality, but also to consider its match with the main materials such as procurement, transportation and other issues. In short, as long as the equipment selection is reasonable, reliable performance, normal operation, matching raw material selection, stable quality, timely supply, reasonable production process parameters, tooling apparatus to ensure that the self-hardening resin sand casting can control and reduce the casting costs, bringing development and benefits to enterprises.

Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of sand reclamation equipment,foundry machines,Sand casting equipment,GS high efficiency rotary mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.